<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<style>
.droptarget {
    float: left; 
    width: 100px; 
    height: 35px;
    margin: 15px;
    padding: 10px;
    border: 1px solid #aaaaaa;
}
</style>
</head>
<body>
<p>在两个矩形框中来回拖动 p 元素:</p>

<div class="droptarget">
  <p id="dragtarget" draggable="true">拖动我!</p>
</div>

<div class="droptarget"></div>

<p style="clear:both;"></p>

<p id="demo"></p>

<script>
/* Events fired on the drag target */
document.ondragstart = function(event) {
    event.dataTransfer.setData("Text", event.target.id);
};

document.ondrag = function(event) {
    document.getElementById("demo").innerHTML = "p 元素正在拖动";
};

/* Events fired on the drop target */
document.ondragover = function(event) {
    event.preventDefault();
};

document.ondrop = function(event) {
    if ( event.target.className == "droptarget" ) {
        var data = event.dataTransfer.getData("Text");
        event.target.appendChild(document.getElementById(data));
        document.getElementById("demo").innerHTML = "p 元素已被拖动";
    }
};
</script>

</body>
</html>
